Kim Young-Jin, Chin Won-Jong, Jeon Se-Jin
Department of Infrastructure Safety Research, Korea Institute of Civil Engineering and Building Technology, 283, Goyang-daero, Ilsanseo-gu, Goyang-si, Gyeonggi-do 10223, Korea.
Department of Civil Systems Engineering, Ajou University, 206, Worldcup-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16499, Korea.
Materials (Basel). 2020 Sep 30;13(19):4364. doi: 10.3390/ma13194364.
More precast concrete structures have recently been constructed due to their many advantages when compared to conventional cast-in-place construction. Structural behavior at the joints between the precast segments can significantly affect the overall integrity, safety, and serviceability of the structure. In this study, therefore, the interface shear strength of high-strength precast members was investigated by performing push-off tests with the following variables: compressive strength of precast members, dry or wet joint, number and height of shear keys, joint width, filler type, curing temperature, and lateral compressive stress. The test results were analyzed to reveal the effect of each test variable on the joint shear strengths of the specimens. For instance, the failure loads were increased by 14-140%, depending on the lateral compressive stress, as the specified compressive strength of the precast members was increased from 80 to 150 MPa in the dry joints. The failure loads of the wet joints strongly depended on the strength of the filler rather than on that of the precast members and, as a result, the specimen with ultra-high-strength concrete filler was 46-48% stronger than those with high-strength mortar filler. The shear strengths of various joint types obtained from the test were further analyzed in comparison with the predictive equations of Japan Society of Civil Engineers (JSCE) and American Association of State Highway and Transportation Officials (AASHTO) with the aim of validating the appropriateness of these design provisions. In particular, an improved value of a coefficient in the JSCE equation is proposed to cover a range of compressive strengths in various precast members and filling materials.
与传统的现浇施工相比，由于预制混凝土结构具有诸多优点，近年来建造了更多的预制混凝土结构。预制构件之间节点处的结构性能会显著影响结构的整体完整性、安全性和适用性。因此，在本研究中，通过进行推出试验，研究了高强预制构件的界面抗剪强度，试验变量如下：预制构件的抗压强度、干接缝或湿接缝、抗剪键的数量和高度、接缝宽度、填充材料类型、养护温度和侧向压应力。对试验结果进行了分析，以揭示每个试验变量对试件节点抗剪强度的影响。例如，在干接缝中，随着预制构件的规定抗压强度从80MPa提高到150MPa，根据侧向压应力的不同，破坏荷载增加了14% - 140%。湿接缝的破坏荷载很大程度上取决于填充材料的强度，而不是预制构件的强度，因此，采用超高强混凝土填充材料的试件比采用高强砂浆填充材料的试件强度高46% - 48%。为了验证这些设计规定的适用性，将试验得到的各种节点类型的抗剪强度与日本土木工程师协会（JSCE）和美国州公路与运输官员协会（AASHTO）的预测方程进行了进一步比较分析。特别是，提出了JSCE方程中一个系数的改进值，以涵盖各种预制构件和填充材料的抗压强度范围。
